Prismo logo   Chromachron: The Color-Time-Clock that Creates Time

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About Chromachron

Chromachron is a Swiss designer clock that displays the time based on the color-time-circle. This software brings the original Swiss Made wristwatch to your Mac desktop. The name Chromachron stems from the Greek; Chroma means color and Chronos time. This application is made with REALbasic. Freeware by Prismo.

Animated Chromachron clock

Software Download

Icon Chromachron 1.1 400 kB, BinHex encoded StuffIt archive
Icon Chromachron 1.1 (Carbon) 850 kB, BinHex encoded StuffIt archive

The minimum system requirements for Chromachron are:

  • Power Macintosh with color display
  • Mac OS 8.0 or later or Mac OS X 10.0 or later (Carbon version)
  • 1.6 MB of RAM (2.2 MB for Carbon version)

The Color-Time-Circle and Color-Time-Clock

The combination of color and time leads to the color-time-circle. The color-time-circle represents the course of the day by light and color degrees. The day has twelve hours and each hour is assigned a special color. The brightest color, yellow, is 12 noon, when the sun is at its zenith.

How to Read the Clock?

On a chronometer time is shown by hands and numerals. Differently on Chromachron, the color-time-watch: Its face is not a dial but a color-time-circle, over which a black disk revolves with a piece cut out as large as a color segment. The disk revolves with the speed of one color area per hour. The disk cut-out indicates the time.

If, for example, this stands on yellow, it is 12:00 noon. The more to be seen of the following color, the nearer the next hour. More time reading examples:

  • 12:00 means yellow
  • 12:30 means half orange
  • 12:45 means 1/4 to orange

The Chromachron animation above displays the time in time lapse in half hour steps.

Resources and Photography

Resources available on Net covering this unique color watch that creates time.

What is time? If I am asked what is time, I do not know. If I am not asked, I know.

Chromachron wristwatch

Photo of Chromachron wristwatch ACHR 116 885 (December 1988)
Edition Tian Harlan, Switzerland. Chrome model with genuine leather waterproof strap.
Ref. No. CC II – URO 10, 20m waterresistant, Sapphire glass 1600, Swiss Made Quartz.

«No time! No time!», is the hectic shout of the rabbit as he hops away in «Alice in Wonderland».


Frequently Asked Questions (FAQ)

1. Question: Where can I buy a Chromachron watch? Where can I have a broken-down Chromachron watch repaired or get spare parts as straps?
1. Answer: TimeDesign sells Chromachron wristwatches online and ships them worldwide. TimeDesign offered a Chromachron service & repair located in Germany and Switzerland in the past.
2. Question: How accurate is Chromachron?
2. Answer: The clock gets updated about every minute which equals an angle rotation of 0.5 degree and is as precise as your Mac's system clock.
3. Question: Can it display the date?
3. Answer: Yes. The Get Info command displays the current date. The original Chromachron watch had no date display.
4. Question: How can I set the 24 hour respectively am/pm mode?
4. Answer: Use the Get Info command to display the current time. The color-time-clock sports only a 12 hour circle and you can always look out of the window to see if it's day or night. I might perhaps darken the color-circle at night for people without a window. Sun is light and light is color.
5. Question: Can the clock display a second time zone or be used as a stop watch?
5. Answer: No. Simplicity was the goal of the designer and it's also mine.
6. Question: When will the Chromachron application be available for Windows?
6. Answer: Sorry, Chromachron is Mac only for the time being.
7. Question: Where can I find a native Mac OS X application of the Chromachron watch?
7. Answer: Download ChromaCocoa 1.1 for Mac OS X 10.2.1 or later.
8. Question: Will Chromachron be released as a Dashboard Widget mini-application for Mac OS X 10.4 (Tiger)?
8. Answer: Prismo is looking forward to get more technical details from Apple on how to implement an accessory. Stay tuned.

Known Problems

  • If you get the message "An exception of class NilObjectException was not handled. The application must shut down." when opening the application or after using Chromachron for a while, increase the memory allocation in the Finder's Get Info dialog under Memory Requirements.
  • On starting up Chromachron the black disk is displayed with a delay of a few seconds (time depends on the processor power of your Mac).
  • Balloon help is not working for the menu bar and the Chromachron Guide menu entry (Help menu).


Answers to common technical questions and free upgrades appear periodically on this Chromachron Home Page. For bug reports and feedback about the software, please write to Prismo.

Version History

Version Date Remarks
1.1 24 June 2001
  • Added a Get Info command to display the current date and time (File menu). The formats correspond to your system settings.
  • Works now better with read-only volumes where the preferences cannot be saved in the active System folder (e.g. when the computer is started from a System CD-ROM). Chromachron uses the default settings.
  • Improved exception handling for graphics operations and preferences file access.
  • Built the application with REALbasic 3.2.1.
  • The Application menu no longer shows the ".app" extension (Mac OS X only).
  • The window titles need more space and might be truncated (Mac OS X only).
27 May 2001
  • Built the Carbon application with REALbasic 3.2.
  • For Mac OS 8.6 to 9.x the application requires CarbonLib 1.1 or later to run.
1.0.3 27 April 2001
  • Improved error handling during low memory conditions.
1.0.2 21 April 2001
  • Built the application with REALbasic 3.0 to reduce processor usage when idle.
  • Balloon help for menus is no longer working.
1.0.1 7 January 2001
  • The preferences are correctly saved, not only when the application quits.
  • The color-time-circle better matches the original wristwatch on liquid crystal display (LCD) and CRT monitors.
  • Joined the Made with REALbasic Partner Program as "Premier Partner".
1.0 1 January 2001
  • The first public release.

Project Chromachron

Future Plans

  • Better support for a wide range of color monitors like LCDs and CRTs.
  • Faster, flicker-free redrawing when the clock updates.
  • Anti-aliasing for the black disc (arc drawing routine wanted).
  • Shadow effects for the clock.
  • Different clock sizes, maybe by resizing the window.
  • Round clock window instead of a rectangular shape.
  • Time simulation to demo the software with its color-time-system.
  • Optimized performance, low memory and hard disk footprint.
  • Nicer and smoother icon resources (more photo-realistic for Mac OS X).
  • Mac OS X and Palm OS implementations.
  • Translation into German, French, Italian, Spanish or other languages according to demand.

Technical Notes

The software was developed as a 68k and Carbon application with REALbasic 2.1.2 and 3.x Standard Edition. Numerous tests were conducted on a Power Mac 8600/200, G3/300 beige, iBook and G4/500 Dual with Mac OS 8.1, 8.6, 9.0.4 and 9.1 (U.S. English and Swiss German) on color TFT flat-panel displays and cathode-ray tube (CRT) monitors.

People and Patents

Written by Marcel Büchi. Design by Tian Harlan. REALbasic support and the book REALbasic: The Definitive Guide by Matt Neuburg. The principle of Chromachron was patented in 1973 by the engineer Tian Harlan. Swiss Pat. No. 613 587, further patents in Germany, USA and Japan.

Made with REALbasic logo

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